ZyXEL Communications AMG1312-T10D User Manual Download

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Chapter 6 Wireless

AMG1312-T10D User’s Guide

6.10 Technical Reference

This section discusses wireless LANs in depth.

6.10.1 Additional Wireless Terms

The following table describes some wireless network terms and acronyms used in the Device’s web
configurator.

6.10.2 Wireless Security Overview

By their nature, radio communications are simple to intercept. For wireless data networks, this
means that anyone within range of a wireless network without security can not only read the data
passing over the airwaves, but also join the network. Once an unauthorized person has access to
the network, he or she can steal information or introduce malware (malicious software) intended to
compromise the network. For these reasons, a variety of security systems have been developed to
ensure that only authorized people can use a wireless data network, or understand the data carried
on it.

These security standards do two things. First, they authenticate. This means that only people
presenting the right credentials (often a username and password, or a “key” phrase) can access the
network. Second, they encrypt. This means that the information sent over the air is encoded. Only
people with the code key can understand the information, and only people who have been
authenticated are given the code key.

These security standards vary in effectiveness. Some can be broken, such as the old Wired
Equivalent Protocol (WEP). Using WEP is better than using no security at all, but it will not keep a
determined attacker out. Other security standards are secure in themselves but can be broken if a
user does not use them properly. For example, the WPA2-PSK security standard is very secure if
you use a long key which is difficult for an attacker’s software to guess - for example, a twenty-
letter long string of apparently random numbers and letters - but it is not very secure if you use a
short key which is very easy to guess - for example, a three-letter word from the dictionary.

Table 23

Additional Wireless Terms

TERM

DESCRIPTION

RTS/CTS Threshold

In a wireless network which covers a large area, wireless devices are sometimes not
aware of each other’s presence. This may cause them to send information to the AP at
the same time and result in information colliding and not getting through.

By setting this value lower than the default value, the wireless devices must
sometimes get permission to send information to the Device. The lower the value, the
more often the devices must get permission.

If this value is greater than the fragmentation threshold value (see below), then
wireless devices never have to get permission to send information to the Device.

Preamble

A preamble affects the timing in your wireless network. There are two preamble
modes: long and short.

If a device uses a different preamble mode than the Device

does, it cannot communicate with the Device.

Authentication

The process of verifying whether a wireless device is allowed to use the wireless
network.

Fragmentation
Threshold

A small fragmentation threshold is recommended for busy networks, while a larger
threshold provides faster performance if the network is not very busy.